Yes i have enabled xmp for my rams and they have been running at 3000 mhz for a while without any crash or instabilty, i even tried with a pair of different rams but the issue remains. I'll try with default settings and report asap.
Also i've noticed that in game if i close absolutely everything that isn't my main game, the performance increase and the stutter is less noticeable. (fps never goes under 100)
I would say: 'Always go minimalist'. Shut down any program that is running that isn't 100% necessary. Don't install any extra utilities etc. Don't ever use motherboard utilities. When you install GPU drivers, don't choose Geforce Experience, don't tick HDMI, PhysX etc if you know you are never going to use it. To go even further, you can debloat win10. Just google it. Check Msconfig what services start with the system. Filter out Windows Services. Disable anything not necessary.
Eliminate variables.
Now, my brother had a stuttering issue out of nowhere. We tried different GPU drivers, checked BIOS settings, everything was normal, didn't change anything. Well, until...he uninstalled the mouse driver for some trending mouse he got from China. Apparently. not that great drivers.
I had never heard of the brand. That is why I suggested he uninstall it. It was the last unknown variable. We had previously removed every piece of Corsair etc software.
Lesson learned, drivers suck. It's not like other companies from other countries are immune to the same problem.